Commencing within the time period extending from the last quarter of 1973 through at least the first quarter of 1974, the world, particularly the industrialized and energy-consuming nations, was suddenly made acutely aware of the existence of the Organization of Petroleum Exporting Countries, acronymously and subsequently infamously known as OPEC, which precipitated the first major energy crisis of modern times through means of a substantial curtailment of a large percentage of the world's crude oil supply output production as well as a several-fold increase in price of such crude oil. These factors, in turn, effectively increased the price of, for example, automotive gasoline, home heating oil, aircraft jet fuel, and all petroleum oil products in general, to a substantial degree. Consequently, this dominance and effective control of the world's crude oil supplies and pricing structure by OPEC underscored the need for the world's industrialized nations to economically develop other sources of energy, and for all nations of the world to conservatively use existing crude oil supplies and sources.
In the conservative energy use sphere, such as, for example, in connection with the automotive industry, various techniques have been employed to render the newest automobiles the most fuel-efficient. In addition to the manufacture of improved automotive engines and transmissions, for example, one mode or technique that has been successfully employed has been to structurally re-design the automobiles so as to provide the same with substantially the same passenger and cargo payload or accommodation volume while simultaneously reducing the overall size of the automobile. In addition, the newest automobiles are being fabricated from materials, in whole or in part, which provide favorable strength-to-weight characteristics as compared to previously conventional thick-gauge metal. These various design and material improvements have effectively reduced the overall weight of the automobiles which has led to a demonstrative improvement in the fuel efficiency of the automobiles as determined by the variously available automotive miles-per-gallon test data.
Similar improvements and technological advances have assuredly been achieved in the aircraft industry. In addition to vastly improved aircraft engines, the most recently produced fleets of aircraft have been fabricated with improved materials, such as, for example, aluminum, titanium, and the like, which have simultaneously reduced the gross weight of the aircraft and have permitted the same to fly with substantially improved, that is, reduced, fuel consumption.
Further improvements have yet to be made, however, in connection with the structural framework system of the aircraft, particularly those portions of the system which define the interconnections between the monocoque fuselage of the aircraft and the aircraft's wings, horizontal stabilizers, and the vertical tail fin. With respect to the structural integration system conventionally employed, for example, to interconnect the aircraft's vertical tail fin with the fuselage, the fin structure is attached to aft body structure which, in turn, is attached to the monocoque fuselage structure. In this manner, vertical fin and horizontal stabilizer loads are necessarily initially transferred or transmitted to the aft body structure and then secondarily transmitted or distributed by the aft body into the monocoque fuselage structure.
A need therefore exists for a structural re-designing of the empennage-fuselage structural integration system whereby the tail fin and horizontal stabilizer loads would be able to be transferred or transmitted directly into the fuselage structure. In this manner, the number of joints defined between the empennage and the fuselage may be substantially reduced as may the extent of the load paths. These factors will in turn lead to a substantial reduction in material and construction-assembly manufacturing costs as well as a significant decrease in the gross weight of the aircraft empennage assembly which will favorably affect operating costs.